CELLULOSE DIGESTION AND CELLULASE REGULATION AND DISTRIBUTION IN FIBROBACTER-SUCCINOGENES SUBSP SUCCINOGENES S85
CELLULOSE DIGESTION AND CELLULASE REGULATION AND DISTRIBUTION IN FIBROBACTER-SUCCINOGENES SUBSP SUCCINOGENES S85
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DOI：
10.1128/aem.56.5.1221-1228.1990
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发表时间：
1990-05-01
影响因子：
4.4
通讯作者：
FORSBERG, CW
中科院分区：
文献类型：
--
作者：
HUANG, L;FORSBERG, CW
产琥珀酸纤维杆菌亚种无论是从葡萄糖、纤维二糖还是纤维素培养物接种，琥珀酸菌S85都能在微晶纤维素上无滞后地启动生长。在纤维素上生长期间，没有可溶性碳水化合物的积累。当生长培养基含有葡萄糖或纤维二糖与微晶纤维素的组合时，纤维素消化存在滞后，直到所有的可溶性糖都被利用，这表明影响纤维素消化的终产物反馈机制。Cl-刺激的纤维二糖酶和周质纤维糊精酶在所有测试的生长条件下产生，表明组成型合成。这两种纤维二糖糖苷酶的细胞相关的，直到生长的稳定期，而蛋白质抗原相关的Cl-刺激的纤维二糖糖苷酶和比例的内切葡聚糖酶被释放到细胞外培养液在生长过程中，无论基板。免疫电子显微镜的细胞与Cl-刺激的纤维二糖酶的多克隆抗体作为第一抗体和10 nm直径的金颗粒缀合到山羊抗兔抗体作为第二抗体，揭示了突出的外表面，选择性地用金标记，这表明Cl-stimulated纤维二糖酶位于突起。这些数据支持了突起在纤维素水解中起作用的论点;然而，这种解释由于抗体与大量具有相关抗原表位的其他蛋白质的反应性而变得复杂。
Fibrobacter succinogenes subsp. succinogenes S85 initiated growth on microcyrstalline cellulose without a lag whether inoculated from a glucose, cellobiose, or cellulose culture. During growth on cellulose, there was no accumulation of soluble carbohydrate. When the growth medium contained either glucose or celloboise in combination with microcrystalline cellulose, there was a lag in cellulose digestion until all of the soluble sugar had been utilized, suggesting and end product feedback mechanism that affects cellulose digestion. Cl-stimulated cellobiosidase and periplasmic cellodextrinase were produced under all growth conditions tested, indicating constitutive synthesis. Both cellobiosidases were cell associated until the stationary phase of growth, whereas proteins antigenically related to the Cl-stimulated cellobiosidase and a proportion of the endoglucanase were released into the extracellular culture fluid during growth, irrespective of the substrate. Immunoelectron microscopy of cells with a polyclonal antibody to Cl-stimulated cellobiosidase as the primary antibody and 10-nm-diameter gold particles conjugated to goat anti-rabbit antibodies as the second antibody revealed protrusions of the outer surface which were selectively labeled with gold, suggesting that Cl-stimualted cellobiosidase was located on the protrusions. These data support the contention that the protrusions have a role in cellulose hydrolysis; however, this interpretation is complicated by reactivity of the antibodies with a large number of other proteins that possess related antigenic epitopes.